Glyceride oil gel paints



United States Patent GLYCERIDE OIL GEL PAINTS Jacobus Rinse,Bernardsville, N.J., assignor to J. W. Ayers & Co., Easton, Pa., acorporation of Delaware No Drawing. Application March 9, 1956 Serial No.570,414

, 11 Claims. (Cl. 106-253) This invention relates to glyceride oil gelcoating compositions and more particularly to dripless or socalled gelpaints and their preparation from drying oils i.e., those classifiedeither as drying oils or as semidrying oils, by reaction with certainaluminum acylates or alkoxides hereinafter defined.

In my copending application Serial No. 439,473, filed June 25, 1954, Ihave disclosed that alkoxy aluminum acylates may be reacted with monoordi-glycerides of higher molecular fatty acids to produce stable coatingcompositions which will thicken and harden rapidly when applied in filmform.

The dripless paints proposed in the literature or sold to'the trade onlypartially satisfy the demands as to quality or availability, for theyare either costly to produce' or they are lacking in water resistance,brushing, flowing or drying properties.

An object of the present invention is to provide superior dripless paintat an acceptably low cost. Another object is to produce such paintsusing inert pigments which will dry at a satisfactorily rapid ratewithout requiring the addition of excessive amounts of the usual metaldriers or drying pigments which would lessen the life of the paint film.

Broadly considered, the process of the' invention may be defined asinvolving the production of paint and varnish bases by gelling ahydroxylatedglyceride drying oil through reaction of the same with asmall amount of an aluminum compound compatible with the oil, and havingthe basic formula:

Acyl-O aAl wherein a and b may be acyloxy radicals, may behydrocarbon-oxy radicals, may be an oxo= radical together, and wherein amay be an hydroxy radical provided b is a hydrocarbon-oxy radical.

When the compound reacted with the glyceride oil is an oxo-aluminumacylate or its polymer, the primary product formed appears to be anaddition product in which the oxygen of the glyceryl hydroxy groupattaches to the aluminum atom, and the hydrogen atom of said groupattaches to the oxo oxygen atom. The reaction of the other types ofaluminum compounds with the hydroxylated glyceride oil may beexemplified by the reaction of hydroxy, alkoxy aluminum acylateinvolving the introduction of the fatty acid glyceryl radical into thealuminum compound molecule and the liberation of alcohol. The primaryreaction product appears to have the formula:

OH Fatty acld-glyceryl 0-A1 Q-Acyl The glyceride oil containing freehydroxy groups may be either one of two types. The first type may bedefined as vegetable or animal oils which are commonly Patented Nov. 3,1959 defined'as b'o'died oils and may he produced by heating 7 the oilto a temperature around 300 C. until the viscosity has 'been increasedto at least ten poises at 25 C, and preferably to 50-200 poises. Throughthis heating, monoand diglycerides are formed by splitting, thusproviding the required free hydroxy groups. Examples of such oils aresoybean, linseed and saffiower oils.

The'second type of hydroxylated oils'utilizable in the process may bereferred to as partial esters produced are glycerol, sorbitol, mannitoland particularly, pentaerythritol. Epoxy resins containing free epoxygroups can also be used, and especially those produced from bis-phenoland epichlorohydrine. The quantity of the polyol or epoxy resin usablewith the oil varies between about 120% but usually 2-6%, by weight, issufficient.

The aluminum compounds utilizable in the practice of the presentinvention include hydroxy, alkoxy aluminum acylates and thecorresponding phenoxy compounds; mono-alkoxy aluminum diacylates;dialkoxy aluminum monoacylates and as well the corresponding phenoxycom-,

pounds of all of these alkoxy aluminum acylate com-' pounds; truealuminum triacylates, and oxo-aluminum acylates.

In addition'to the above monomers, the copolymers and mixed polymersproducible from certain of the above aluminum compounds are alsooperable in the practice of the present invention. Such polymers may beobtained from the'hydroxy alkoxy aluminum acylates simply by heating, asto C. or more, and from the dialkoxy aluminum monoacylates andoxo-aluminum acylates by heating them to such temperatures in thepresence of an equivalent amount of Water (with the oxo compound nowater is required), glycol or other polyol, hydroxy carboxylic acid ordicarboxylic acid; Examples of such polymers are diacyloxy,aluminum-oxy-aluminum diacylate and H[O-Al(- X)-],,OR wherein X is ana'cyloxy group and R is a hydrocarbon group.

Processes of preparing the aluminum compounds used in the composition ofthe present invention do not constitute any part of the presentinvention, for they are described in part in the prior art and in partin appli cants, prior copending applications. Examples of and details asto preparation of the oxo-aluminum acylates and the polymers thereof aredisclosed in applicants prior application Serial No. 533,235 filedSeptember 8, 1955.

The hereinbefore mentioned compounds require one 0r. more radicals of alength which impart the required oil compatibility. With thislimitation, the acylate and hydrocarbon radicals may be of any lengthfrom one carbon atom up, although radicals of at least three carbonatoms are preferred. The acylate radicals may be of any structureincluding normal and branched, and saturated and unsaturated, thepreferred acids being fatty acids of higher molecular weight such asoctoic, oleic and stearic acids.

The hydrocarbon radicals of the hydrocarbon-oxy groups contained in thealuminum compounds may be cyclic or acyclic, saturated or unsaturated,straight or branched, and may contain any number of carbon atoms fromone up with the limitation that there must be at least one radical orcombination of radicals of surficient chain length to impart therequired solubility wit the oil to be reacted therewith.

Among the preferred alkoxy groups are the lower mol cular lkyl radicalsof bo h the normal and iso structure, as those containing 3 to 6 carbonatoms. Among the cyclic groups, there may be mentioned the benzylradical, the phenyl radical and the cyclohexyl radical.

The aeylate, alcoholate and phenolate radicals ofthe aluminum compoundsmay be substituted and be derived from dicarboxylic acids, glycols,glycolic acids or from compounds which have been substituted at a carbonatom or atoms by any other atoms or radicals which do not interfere withtherequired activity of the aluminum compounds, as those containingnitrogen or oxygen, as in ether and ester substituent groups or thosecontaining hydrocarbon radicals as in butyland amyl-phenyl radicals.Where the terms alkoxy and phenoxy are employed herein they are usedbroadly to include not only the unsubstituted radicals but also thosewhich are substituted with non-interfering atoms or radicals.

The reaction of the glyceride oils with the aluminum compounds can beaccomplished by heating the mixtures of said ingredients, either bythemselves or in hydrocarbon solution as in mineral spirits, turpentineor an aromatic solvent as xylene, at elevated temperatures suitablybetween about 100 and 250 C. until gelling takes place or until nofurther change in viscosity occurs, the time usually required varyingbetween about 10 and 60 minutes. In connection with the gels produced todate, the preferred conditions involve heating at 160 to 170 C. for fromminutes or more.

The time required for completion of gelation in any particular reactionmay be determined by test, for the treatment is complete when the gel ofthe desired consistency is obtained or when no further increase inviscosity or gel strength is observed. The preferred reaction procedureinvolves mixing and heating the oil and the aluminum compound togetherin the presence of little or no solvent until the gelation reaction iscompleted and then adding the mineral spirits or other hydrocarbon afterthe gel has been cooled. If a specific use is anticipated for the gel,it can be diluted while hot with an appropriate hydrocarbon solvent orpaint thinner compatible with the gelled oil. The diluted glyceride oilgel is then ready for sale to, or use by, compounders of the protectivecoating compositions herein described.

Through this heat treatment a strong chemical combination of thereactants is obtained, and as a result, the coating compositionsemploying such oils possess a high resistance against the action ofmoisture or water.

To determine what time of heating is required to provide gels completelystable to hydrolysis, samples of the reaction product in a test run maybe checked from time to time by adding a few drops of water to grams ofthe same, heating the mixture to a temperature between 100 and 150 C.until all water is boiled off,

cooling the mass, then replacing any hydrocarbon solvent evaporatedduring the heating and testing the strength of the gel. If no loss ingel strength is observed, then the product is hydrolysis stable, forhydrolyzable gels thin down and weaken if they react with water.

If the paint manufacturer prefers to grind his pigments in non-gelledvehicles, he may use the alcoholized oil and after grinding he can thenadd the aluminum compound, to obtain a gelled paint, which in manyrespects will be comparable to the gel paints made by the first method.

The quantity of aluminum compound required to effect gelation of theglyceride oils depends upon the nature of the specific compoundsemployed and'upon other factors, but ordinarily from 0.5 up to 10% issuflicient, depending upon many factors, including the desired degreeof'softness or stiffness required in the gel to be produced. In. anyparticular formulation, proper thix otropic gel properties can beobtained only if the components are carefully proportioned within fairlynarrow and stirred into the mass.

In producing the coating composition of the present invention, pigments,extenders, resins, thinners, driers and other conventional paintmaterials can be added either before or after the gel-forming reactionhas been carried out, depending upon the activity of the gelling agentand the desired properties in the gel paint. If the active additions aremade before the grinding operation is carried out, then a heat treatmentto produce superior gels is no longer possible. When the gelling isdelayed to the end of the paint production process, the procedure has anadvantage in that the oils are liquid during compounding and thus areeasily handled. It is surprising, however, that when the oils are gelledwith the aid of heat in the initial step, the jelly-like product may becompounded with the pigment and other ingredients without appreciabledifficulty, for the gels possess excellent wetting properties forpigments.

An important embodiment of the invention follows from the discovery thatpaints can be successfully pro.- duced using inert (i.e. zinc and leadfree) pigments exclusively, as titanium dioxide, lead titanate andcarbon black. No zinc or lead pigments are required to provideadequately fast drying. Paint compositions of high pigment volumeconcentrations of 50% or even as high as 60 or 70% can be prepared underthe practice of the invention and yet excellent flow propertiesretained.

Whether they contain active pigments (as zinc oxide and white lead) ornot the paint compositions of the present invention dry rapidly from theaction of the aluminum compound therein, but normaly the addition of theregular paint driers is desirable or needed, examples being lead, cobaltand other metal resinates, naphthenates and oleates, but smallerquantities are required than are needed in the absence of the aluminumcompound addition.

The thixotropic qualities of the paints of the present invention preventsettling of pigments and facilitate spreading with the brush without anyhindrance to the flowing qualities of the paint. The quantity ofaluminum is so small in the coating that this metal exercises no harmfulinfluence on the lasting flexibility of the coatings or on itsdurability. Beside the improved rheological properties of the paint, thedrying properties are improved and the paint penetrates less into poroussurfaces to which it is applied.

The invention is illustrated by the following examples, wherein theamounts given are parts by weight.

Example 1 One hundred parts of bodied linseed oil of Z; viscosity and AV25 are heated to C. in a kettle whereupon 3% of hydroxy isopropoxyaluminum stearate solution in mineral spirits (67%) is added and heatedfor one hour at 160-190" C. The resulting gel is poured out of thekettle, and it stitfens somewhat on cooling. For producing painttherefrom one hundred parts of the gelled oil are mixed with one hundredparts of mineral spirits, 150 parts of rutile titanium dioxide and 2parts of cobalt naphthenate. An excellent thixotropic nonpenetratingpaint is thereby obtained.

Example 2 One hundred parts of linseed oil are mixed with 6 parts ofbis-phenol-epichlorhydrin resin (Epon 1001) and heated at 300 C. duringstirring until a homogeneous mass is obtained. The resulting mixture isthen heated to 150 C. and 6 parts of polymerized oxo-aluminum oleatedissolved in 6 parts of mineral spirits are added The temperature of theresulting mixture is then raised to 180 C. and heated for 30 minutesuntil a stiff gel is obtained.

The thus obtained gelled linseed oil is then dissolved in an equalamount of mineral spirits. Thereupon 40 parts of the resulting solutionare mixed with 40 parts of titanium calcium sulfate p gment (Iitanox.RCHI) and the resulting mixture is then ground, thinned with 10 partsof mineral spirits and 0.5 part of lead-cobalt naphthenate or otherconventional drier. A thixotropic paint having good flowing propertiesis thereby obtained.

Example 3 One hundred parts of oiticica oil is mixed with 5 parts ofhydroxy phenoxy aluminum oleate and heated at 200 C. until a thickenedmass has been obtained. Thereupon the mass is thinned by the addition of100 parts of mineral spirits and as a result a strong gel is obtained.Next the gel is mixed and ground with rutile titanium dioxide in theratio of 1 part gel, 1 part pigment and 1 part mineral spirits. Theresulting product is a rapidly drying paint. (Oiticica oil under theconditions of the reaction with the aluminum compounds produces therequired hydroxyl groups, for such oil contains the group, CH CO whichis capable of enolyzing into the group, -CI-I=C(OH)-.)

Example 4 Ten parts of carbon black are ground in 60 parts of linseedoil which has theretofore been alcoholized by reaction With 1.5 parts ofsorbitol. Thereupon the conventional drier and 6% of aluminumdi-isopropylate, monoethylglycolate are added and the mass is vigorouslystirred.

It should be understod that the present invention is not limited to thedetails herein described but that it extends to all equivalentmaterials, conditions and procedures which will occur to those skilledin the art upon consideration of the scope of the claims appenededhereto.

I claim:

l. A thixotropic gel coating composition containing the gelatinousreaction product of an hydroxylated glyceride drying oil and an aluminumcompound compatible with said oil selected from the group consisting ofthose compounds defined by the basic formula:

Acyl-O aAl wherein a and b respectively are selected from the groupconsisting of acyloxy and acyloxy, acyloxy and hydrocarbonoxy,hydrocarbonoxy and hydrocarbonoxy, hydrocarbonoxy and hydroxy, and anx0: radical together.

2. The gel defined in claim 1 wherein the oil used is a bodied dryingoil containing free hydroxy groups.

3. The gel defined in claim 1 wherein the oil used is a partial ester ofa drying oil with a polyol of at least three hydroxy groups;

4. The gel defined in claim 1 wherein the oil component is oiticica oil.

5. Thixotropic gel paints having a. pigment content consisting of inertpigments, and containing the gelatinous reaction product of anhydroxylated glyceride drying oil and an aluminum compound compatiblewith said oil selected from the group consisting of those compoundsdefined by the basic formula:

Aeyl-O a-Al wherein a and b respectively are selected from the groupconsisting of acyloxy and acyloxy, acyloxy and hydrocarbonoxy,hydrocarbonoxy and hydrocarbonoxy, hydrocarbonoxy and hydroxy, and an0x0: radical together.

6. A titanium dioxide. pig en ed thi o p nt 6 containing the gelatinousreaction product of an hydroxylated glyceride drying oil and an aluminumcompound compatible with said oil selected from the group consisting ofthose compounds defined by the basic formula:

Acyl-O (17A! 7 b wherein a and b respectively are selected from thegroupconsisting of acyloxy and acyloxy, acyloxy and hydrocarbonoxy,hydrocarbonoxy and hydrocarbonoxy, hydrocarbonoxy and hydroxy, and an0x0 radical together.

7. The gel defined in claim 1 wherein the aluminum compound used is analkoxy hydroxy aluminum acylate.

8. The gel defined in claim lwherein the aluminum compound used is anoxo-aluminum acylate.

9. A process for producing thixotropic gel paints which comprisesforming a homogeneous mixture of a gelatinous reaction product of anhydroxylated glyceride drying oil and an aluminum compound compatiblewith said oil selected from the group consisting of those compoundsdefined by the basic formula:

Acyl-O a-Al oil and from 0.5-10% thereof of an aluminum compoundcompatible with said oil selected from the group consisting of thosecompounds defined by the basic formula:

Acyl-O wherein a and b respectively are selected from the groupconsisting of acyloxy and acyloxy, acyloxy and hydrocarbonoxy,hydrocarbonoxy and hydrocarbonoxy, hydrocarbonoxy and hydroxy, and anoxo= radical together, and forming a homogeneous mixture of thegelatinous reaction product obtained with pigment, thinner and drier.

11. The process defined in claim 10 wherein the reaction between the oiland the aluminum compound is effected by heating to a temperature offrom to 250 C. until the reaction is complete.

References Cited in the file of this patent UNITED STATES PATENTS2,464,202 Rust Mar. 15, 1949 2,469,041 Jones May 3, 1949 2,582,833 HunnJan. 15, 1952 2,599,553 Hotten June 10, 1952 2,736,666 Beacham Feb. 28,1956 2,752,262 Dunlap June 26, 1956 2,803,609 Schlen er A g- 20, 1957

1. A THIXOTROPIC GEL COATING COMPOSITION CONTAINING THE GELATINOUSREACTION PRODUCT OF AN HYDROXYLATED GLYCERIDE DRYING OIL AND AN ALUMINUMCOMPOUND COMPATIBLE WITH SAID OIL SELECTED FROM THE GROUP CONSISTING OFTHOSE COMPOUNDS DEFINED BY THE FORMULA: